The present invention relates to a key input system for an electronic apparatus such as an electronic calculator and, more particularly, to a confirmation sound generation system for indicating effective key input operation in an electronic apparatus.
An electronic calculator has been developed, which includes a sound generation system for developing a confirmation sound in response to actuation of any key included in a keyboard panel. A typical confirmation sound generation system is described in copending application, ELECTRONIC CALCULATOR WITH ACOUSTICALLY ALARMING CAPABILITIES, Ser. No. 845,977, filed Oct. 27, 1977 by Isamu Washizuka and Shintaro Hashimoto and assigned to the same assignee as the present application.
The above-mentioned key input confirmation system is very effective for an electronic calculator including minimum stroke keyboard switches such as disclosed in copending application, ELECTRONIC CALCULATOR WITH NO PROTRUDING KEY TOPS, Ser. No. 843,047 and now U.S. Pat. No. 4,158,230, filed Oct. 17, 1977 by Isamu Washizuka, Shintaro Hashimoto, Sadakatsu Hashimoto and Shigeki Komaki and assigned to the same assignee as the present application.
In the conventional confirmation sound generation system, the confirmation sound is always developed upon actuation of any key included in the keyboard panel. Therefore, the operator may advance to the following key and actuate the said key without regard to the fact that the previously conducted key input operation may not be effective or correct. This will cause erroneous key input operation.
Accordingly, an object of the present invention is to provide an improved confirmation sound generation system for an electronic apparatus including a keyboard panel.
Another object of the present invention is to provide a confirmation sound generation system for an electronic calculator in order to indicate effective key input operation.
Still another object of the present invention is to provide a novel key input system, which minimizes erroneous key input operation in an electronic apparatus.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating a preferred embodiment of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, an electronic calculator is provided with a confirmation sound generation system, and a determination system for determining whether the presently conducted key input operation is effective or correct. The confirmation sound generation system is enabled upon generation of a determination signal derived from the determination system, thereby developing the confirmation sound only when an effective key input operation is conducted.
In a preferred form, the confirmation sound will not be generated upon actuation of any key other than the error clear key in the case where the electronic calculator is placed in the error condition. In the numeral information introduction operation, the confirmation sound is generated upon actuation of numeral keys, but the confirmation sound will not be generated when the numeral keys are operated to introduce the numeral information exceeding the digit capacity of the electronic calculator.
Moreover, the confirmation sound is not generated when the function keys such as .times. key, .div. key and % key are actuated without the advance introduction of the appropriate numerical information.